Thanks - glad it was helpful.Those steppers sound good. I have used lower current / lower torque ones on a mobile robot and they were great. I used the Adafruit motor driver board and AccelStepper library.Your definition of racking is correct. I am surprised the one rod does not work since it mechanically connects the sides (well, through the belts in my setup). Make sure the screws are tight and belts fairly tight - not slipping at all. Are you using two motors or one on that axis? If it's two, they may not be moving exactly together. I only use one motor. You could extend that long shaft and put the motor right on that one. If you have a high acceleration on the motor, that could also be an issue - would require a stronger frame. But, yes, you should be able to put a long sha...

Thanks - glad it was helpful.Those steppers sound good. I have used lower current / lower torque ones on a mobile robot and they were great. I used the Adafruit motor driver board and AccelStepper library.Your definition of racking is correct. I am surprised the one rod does not work since it mechanically connects the sides (well, through the belts in my setup). Make sure the screws are tight and belts fairly tight - not slipping at all. Are you using two motors or one on that axis? If it's two, they may not be moving exactly together. I only use one motor. You could extend that long shaft and put the motor right on that one. If you have a high acceleration on the motor, that could also be an issue - would require a stronger frame. But, yes, you should be able to put a long shaft on both ends.Yes, for multiple screws, a custom bracket from angle aluminum or printed may work, and yes, it might be less adjustable. I have not tried that approach.Good luck!

Nice project. Yes, those linear bearings can be expensive, so a lot of projects use v-groove rollers now. The T-Slot version I also published is another approach, albeit more expensive. It is a lot more relaible, though.

I think most CNC type applications assume there are no obstacles in the workspace - avoiding those would clearly change the drawing. There are numerous vector conversion programs - maybe you can go from an intermediate format like gcode?

Thanks. I do not think this approach would be suitable for very high precision positioning. Using stepper motors would help, as well as making sure everything is well tuned. But, there are many XY table hardware options out there that may be more reliable. I have not used them, so cannot make any recommendations. Good luck!